The 13th Workshop on Compression, Text and Algorithms (WCTA 2018) will be held the day after SPIRE, chaired by José Fuentes Sepúlveda, Paweł Gawrychowski and Nicola Prezza. WCTA is a forum primarily for early-stage researchers to present their work; there are no published proceedings so the results presented can also be submitted to most other workshops and conferences. More information will be posted here later.

Important Dates

  • Abstract deadline: September 3rd, 2018 (anywhere on Earth)
  • Notification: September 12th, 2018
  • Workshop: October 12th, 2018

Travel Grants for Students

WCTA is sponsored by BIRDS MSCA RISE 2015 project. Thank you to the BIRDS project, there are multiple travel grants for students. For application, please send an email to WCTA chairs.

  • Application deadline: September 3rd, 2018 (anywhere on Earth)
  • Notification: September 12th, 2018

Invited Speakers

Jérémy Barbay
Jérémy Barbay is assistant professor in the Department of Computer Science at University of Chile. His research interests include the refined analysis of adaptive algorithms and compressed data structures, systems for collective quality control, and the experimental evaluation of pedagogical techniques. In parallel with his research in theoretical computer science, he is directing a project http://teachingislearning.cl aiming to apply new technologies (e.g. cell phones, collective quality control) to old pedagogical techniques (e.g. learning via teaching).

Jérémy received his PhD from the university Paris XI (Orsay) in 2002. Since then, he has been postdoctoral fellow at University of British Columbia from 2002 to 2004, and assistant professor at University of Waterloo from 2004 to 2008. Jérémy has participated in the organization of previous editions of SPIRE, Dagstuhl seminars and summer schools, and in the program committee of several national and internacional conferences. He is the author of more than 40 publications on international conferences and journals.

Simon Gog
Simon Gog is currently an applied researcher in the search backend team at eBay Inc. His main research interest is Algorithm Engineering for succinct data structures. Simon is the creator of the Succinct Data Structure Library (SDSL), a C++ framework implementing the highlights of over 40 research publications that has become the gold standard for implementing new results in the field of compact data structures.

Simon received his PhD from Ulm University in 2011, supervised by Enno Ohlebusch. From 2012 to 2014 he continued working on text-indexing problems in the Department of Computing and Information Systems at The University of Melbourne, Australia, where he released the second version of SDSL in 2013 in collaboration with other international researchers. After this period, he has been a postdoctoral research fellow at the Institute of Theoretical Informatics at Karslruhe Insitute of Technology (KIT). He is the author of more than 50 publications in international conferences and journals and served on numerous PC committees as committee member and (co)chair.


08:45 Opening and welcome
09:00 Invited talk
Adaptive Analysis of Algorithms: formalizing oportunism, for (fast) algorithms and (compressed) data structures
Jérémy Barbay
09:50 Sufficient conditions for quasi real time online indexing Eitan Kondratovsky
10:10 Average case analysis of leaf-centric binary tree sources Louisa Seelbach Benkner and Markus Lohrey
10:30 Coffee
10:50 Dynamic variable-to-variable compressor Nieves R. Brisaboa, Antonio Fariña, Gonzalo Navarro,
and Tirso V. Rodeiro
11:10 Document listing on repetitive collections with grammar-compression of the document array Dustin Cobas and Gonzalo Navarro
11:30 Relative compression of trajectories Nieves R. Brisaboa, Adrián
Gómez-Brandón, Gonzalo Navarro, and José R. Paramá
11:50 RePair and all irreducible grammars are upper bounded by high-order empirical entropy Carlos Ochoa and Gonzalo Navarro
12:10 Lunch
14:00 Invited talk
Techniques for efficient text search on a dynamic corpus at scale
Simon Gog
14:50 Coffee
15:10 Assembling omnitigs using hidden-order de Bruijn Graphs Diego Díaz-Domínguez, Djamal Belazzougui, Travis Gagie, Veli Mäkinen, Gonzalo Navarro, and Simon J. Puglisi
15:30 Encoding two-dimensional range top-k queries revisited Seungbum Jo and Srinivasa Rao Satti
15:50 Faster computation of genome mappability Daniel Gibney
16:10 Closing

Programme Chairs

  • José Fuentes Sepúlveda, University of Chile
  • Paweł Gawrychowski, University of Wrocław
  • Nicola Prezza, University of Pisa


Please, submit the abstract by email, in PDF format, to the WTCA co-chairs (jfuentess@dcc.uchile.cl, gawry@cs.uni.wroc.pl, nicola.prezza@di.unipi.it)